Recently the shape of the reactor antineutrino spectrum measured by Daya Bay [1]}, Double CHOOZ [2]}, NEOS [3]}, and RENO [4]} shows more than 10% deviation from model predictions [5]}, [6]}, [7]}. The Taishan Antineutrino Observatory (TAO) [8]} is thus proposed to measure the fine structure in the reactor antineutrino spectrum with as high as possible energy resolution. Such a measurement will provide a reference spectrum for JUNO, and also serve as a benchmark to test nuclear databases. TAO will adopt new technology to reach an energy resolution of \(<2\%/\sqrt{E(\mathrm {MeV})}\)  (\(\sim 4500\)  p.e./MeV), by viewing the Gadolinium-doped LS (GdLS) with Silicon Photomultipliers (SiPMs) of photon detection efficiency \(>50\) %.
